Chuck



May 26,1925. 1,539,282 R. E. SPURR CHUCK Filed July 2, 1920 3 Sheets-Sheet 1 INVENTOR ATTORNEY May 26, 1925.

R.E.SPURR CHUCK Filed J%2, 1920 3 Sheetg-Sheet 2 INVENTOR M2155: dw

ATTORNEY May 26, 1925. 1,539,282

R. E. SPURR CHUCK Filed July 2, 1920 I5 'Sheets-Sheet :5

INVENTOR ATTORNEY Patented May 26, 1925.

or Fret-1 ROBERT E SI-UER,-. on: 13351311011, M ro-H IGA'M ASS'IGNOR- 'ro DODGE 'BROTH'ERS,,OF DETROI'I!,= Mro'HIGAN; A oonr onnmio'rr OF' MICHIGAN;

CHUCK? Application filed iuly 2,

Be itknown that I, Rcnnn'r E. Sienna; a" citizen of the United States; residii'ig at Detroit; Michigan;- have invented? certain new and useftil 'In'ipmvements I C1mc1 s;,o'f Which the following" is a clear, ftill, and exact description; A

My invention relates to chueks -such, for instance; as those'nsedin lathes.arid iny'invention has rerits object" to improve and" simplify the constiti'otion' of this class 01"" devices whereby they are rendered moree'li'icientin use; I

A" ieat-ureot' theinventioif resides in the provision of a chnek having a p'liirality' of sets of j aw's, .each set acting? to automatically center the Work. A furtherfeatnre'resides' in the prov'ision ota chuck" having? a plurality of sets of jaws, the-jawed oii'eset having the capability ofditlerentialmovement ithrespect" to the jaws of another set and in which the jaws of all of the sets move to anton'iatically center the work.

A still further liatur-e of the invention resides in the provision ofa cliuclg 'having'a plurality of setsof j aWs operated by a common iiiea'ns, and in which the diameter of the work at; the points to" be gripped by eithersetof' jaWsdoes' not affect the'abililty of another set 01'' jawsf c-onnected tothe first set to properly gripthe Work;

Other feat-ares and advantages will he come apparentfrom the"folloivingdetailed description and claims when taken in con nectioirwitl'r the accompanying drawings, in yvhiclr Fig. Sisa sidefelevation; v

Fig. isa'detail of oneof thebell crank leversfor operating the jawsgand" Fig; 6 is a detail of oneof the jaws.

Referring to "the dra'wlngs', the chuck con sistsof a supporting structure" designated generally by the nnineral 11 This support ingstructure has-a circular plate 2 for connect-in'g the' chuck tothe inainloodyof the lathe. The chuck is longitudinally aper ture'd at-it's central portion, and thro'ughthe aperture extending through the plate 2 exieze. Serial 393,620.

tends a'cylinder 3"operated hy airpressnre' or otlie'ripower"nieans. The cylinder" 8' has cutaway portions at'i opp'osite sides"thereof, asindic'ated'in Fig. 4, forthe purpose ofper mittin'gjaws l which for convenience may be terinedthe'rear ja'Ws--toapproa'ch near enough together to engage thework piece. Thesejaws areslidalolyfrnounted onthe' plate Qin' any suitable manner; Thefor'ward end of the cylinder'3is'pr0videdWith an en'- larged cylindrical portion 5 having not'ches G cut in diametrically opposite" walls thereof, an'din'the notches 6' are guide'dthe arms 7 of bell-crank levers8; thevo-tl1er arnis o'l eacli'of' said bell-crank levers engaging cutoutpoijtion's 10in the jaws 4. Eachzbelh crank lever Bjis mounted for rocking" more Inent' 011a fnlcruin' ll, which 'fnlcrun'ris sup ported by one end of'a' lever 12, said lever Being keyed to a filler-11111 13" mounted in the framelofthe chnckg Theftilera' 18 may b'econsidered fixed jfnlcrainthe sense that they are inaintainedthe same distance apart by the frame 1, although'they are-permitted limited oscillatory inovernent' in said frame. The f'ulcra 11, on the other ha-11d, are floatmg ftilcra, and the1-eftr-e-- t1ie hell-cranks 8 may oscillate ahont'the fillclit' 11 and may revolve about the fulcra' At its end; re- IHOtGfiOIH the fulcrum 11, eachlever 12 c'ar ries a' jaw 1 F as shown in detail in Fig. 6 and which'niaybefastened to the lever 12 hy screws as shown in Fig: 3, orin'any other snitalile manner. By reasonofthe 'tact-that the bell-cranksb"niay'bothosci'llate upon the 'liilcra' 1'1 and revolve about the ftilc'ra- 13; it is clear" thatif the cylinder 3 niove's towards theriglit, Figi l hotli sets of'jaws 4: and 14, may move to Woilienga'ging position, but theniox ein'ent of jaws of each set toward the center line ofthe'ehucli with the mechanism so eudesc rilied; woulcl 'n'o't necessarily he in' unison:

In Fig. l I ha'veshowi'raworlt pieee Aein position grip pedliy'tlie' j was. It this Workpiece were of s'u'clr diameter at its rear portion that the jaws 4- Were practically 111 0011 tact :Witlnit when open to their greatest eX- tent; then upon movement of the cylinder- 3 tmtheright there would he no movement of rotation of the hell cr anls 8 about their 111 era 11. fiis t-lie enlargement 5-1noved to the right; however, the tnle'ra- 11 would move away from each other, and the levers 12 would rotate on their fulcra 18, and the jaws 1% would move until they engage the workpiece, and in some cases this movement might be of quite considerable extent. On the other hand, if the work-piece were of such diame-- ter at the points engaged by the forward jaws 14, when they were opened to their greatest extent, then movement of the cylinder 3 would cause'practically no rotation of the levers 12 about their fulcra 13, but would cause an oscillation of the levers 8 about their fulcra 11, resulting in the jaws 4 making all the movement necessary to engage the work-piece, the aws 14- standing practically still. Different diameters of work-piece at the points engaged by the jaws would therefore result in different movements of the jaws.

Although the sets of jaws are capable of differential movement with respect to each other, I nevertheless provide means whereby the work-piece will always be automatically centered. In order to do this, I preferably provide arms 15 which are keyed to the fulcra 13, shown clearly in Figs. 2 and 3, said arms being provided with toothed ends 16 and 16 which interengage, so that the jaws 14 will constantly remain at equal distances from the center line of the chuck. Since the bell-cranks 8 are connected for movement in unison to the cylinder 3 and since these bellcranks are connected to the levers 12, the jaws 4 will likewise constantly maintain themselves at equal distances from the center line of the chuck.

In order to effect adjustment of the j aws, the levers 12 carrying the forward jaws are made in two parts, with means for adjustment therebetween. This adjustment may be of any suitable character, and for the purpose of illustration I have shown a member 17 screw-threaded into the righthand portion 18 of the lever 12 and secured thereto by a lock-nut 19. A bolt 20 is passed through a central aperture in the member 17 and is provided with a screw-threaded portion engaging the lefthand portion of the lever 12. A reduced portion 21, of the member 17, acts as a bearing block between the two parts of said lever.

lVhile I ,have'described and shown a pre ferred embodiment of my invention, it is to be understood that variations may be resorted to within the spirit thereof and that parts may be used without others.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: j

1. In a chuck, the combination with a set of jaws, of means connecting said jaws for movement in unison, said means including a lever for each jaw, a second set of jaws, each individual jaw of said second set connected to an individual jaw of the first set through the medium of one of said levers, and means engaging said levers for moving both sets of jaws.

2. In a chuck, the combination with a plurality of sets of movable work engaging jaws, of fixed fulcra for the jaws of one set, floating fulcra for the jaws of another set, and means for connecting said aws.

3. In a chuck, the combination with a set of aws, a fixed fulcrum for supporting each jaw of said set, a second set of jaws, a floating fulcrum for supporting each jaw of said second set, and means for connecting each individual jaw of one set with an individual jaw of the other set.

4. In a chuck, the combination with a set of aws, a fixed fulcrum for supporting each jaw of said set, a second set of jaws, a floating fulcrum'for supporting each jaw of said second set, means for connecting each individual jaw of one set with an individual jaw of the other set, and means for connecting the individual jaws of one of said sets of jaws.

5. In a chuck, the combination with a plurality of sets of movable work engaging j aws, of fixed fulcra, levers carried by said fulcra, each lever having a jaw at one end and a floating fulcrum at the other end, and means carried by the floating fulcra for controlling the aws of another set.

6. In a chuck, the combination with a plurality of sets of movable work engaging jaws, of fixed fulcra, levers carried by said fulcra, each lever llaViIlg a jaw at one end and a floating fulcrum at the other end, means carried by the floating fulcra for c011- trolling the jaws of another set, and means for connecting the jaws mounted on the fixed fulcra so that they are constrained to move together to work centering position.

7. In a chuck, the combination with a pair of levers, of fixed fulcra on which said levers are mounted, jaws carried at one end of each of said levers, a floating fulcrum supported by the other end of each lever, an operating lever on each of said floating fulcra, and jaws carried by said operating levers.

8. In a chuck, the combination with a pair of levers, of fixed fulcra on which said levers are mounted, jaws carried at one end of each of said levers, a floating fulcrum supported by the other end of each lever, a bell-crank lever on each floating fulcrum, a jaw connected to one arm of each bell-crank lever, and means for moving said jaws connected to the other end of each bell-crank lever.

9. In a chuck, the combination with a pair of levers, fixed fulcra on which said levers are mounted, aws carried at one end of each of said levers, a floating fulcrum supporting the other end of each lever, a bell-crank lever oneach floating fulcrum, a jaw connected to one arm of each bell-crank lever, means for moving the jaws, cooperatively related to the other end of each bell-crank lever, and means connecting said first-mentioned levers for movement in unison.

10. In a chuck, the combination with a pair of levers, fixed fulcra on which said levers are mounted, jaws carried at the end of each of said levers, a floating fulcrum supported by the other end of each lever, an operating lever on each of said floating tulcra, jaws controlled in their movement by said operating levers, means for moving said operating levers in unison, and means connecting the fixed fulcra compelling movement of said first-mentioned levers in unison.

11. In a chuck, the combination with a support, of a pair of levers mounted for oscillatory movement in said support but fixed with respect to each other, jaws carried at one end of each oi said levers, a floating fulcrum supported by the other end of each lever, a bell-crank lever on each floating fulcrum, a jaw connected to one arm of each bell-crank lever, means for moving said jaws cooperatively related to the other arm of each bell-crank lever, arms connected to said oscillatory fulcra, said arms having their ends toothed and engaging each other to compel oscillatory movement of said fulcra in unison.

12. In a chuck, the combination with a plurality of sets of movable Work engaging jaws, of means't'or maintaining the jaws of one set equally distant from the center line oi the chuck as said jaws move to work engaging position, means for maintaining the jaws of another set equally distant from the centre line of the chuck as they move to work engaging position, and means for connecting the jaws of one set with those of another set t'or differential movement.

13. In a chuck, the combination with a set of jaws, of a lever to which each jaw is connected, means connecting the levers for movement in unison and hence the jaws, a second set of jaws, levers connected thereto, means connecting said last-mentioned levers for movement in unison, and means for connecting the sets of levers so that a jaw of one set will move a jaw of another set.

14. In a chuck, the combination with a set of jaws, of a lever to which each jaw is connected, a sleeve common to the levers and to which they are articulated for movement in unison, a second set of jaws, levers connected thereto, oscillatory fulcra fixed with respect to each other to which said last-mentioned levers are connected, interengaging toothed ROBERT E. SPURR. \Vitnesses J. R. FUKSE, ALFRED H. KNIGHT. 

